Warming neutralizes host-specific competitive advantages between a native and invasive herbivore.

Area of Science:

• Ecology
• Climate Change Biology
• Invasive Species Research

Background:

• Native-invasive species interactions are key ecosystem drivers.
• The impact of warming on these interactions, especially competition, is not well understood.
• Resource availability and host plant type can influence competitive dynamics.

Purpose of the Study:

• To investigate how warming affects native (Pieris canidia) and invasive (Pieris rapae) herbivores under intraspecific and interspecific competition.
• To determine if warming impacts are dependent on host plants and resource availability.
• To assess discrepancies in thermal performance between intraspecific and interspecific competition.

Main Methods:

• Examined the performance of two competing herbivores on two host plants under control and elevated temperature conditions (3°C, 6°C).
• Utilized environmental chambers to control temperature settings.
• Analyzed development and growth metrics to assess competitive outcomes.

Main Results:

• Warming benefited the development and growth of both Pieris species under intraspecific competition, with host-plant dependency.
• Warming neutralized the competitive advantages of either native or invasive Pieris species during interspecific competition, also in a host-plant dependent manner.
• A discrepancy was observed in species thermal performance between intraspecific and interspecific competition.

Conclusions:

• Warming-induced shifts in competitive status between native and invasive species may significantly alter ecosystems globally.
• Current thermal performance models should prioritize data from interspecific competition studies for accurate predictions under warming.
• Host plant specificity plays a critical role in mediating the effects of warming on native-invasive species interactions.